JP2005178065A - Medium for ink jet recording and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium for ink jet recording which makes the ozone resistance of a formed image excellent over a long period and enables attainment of an image of high gloss and high density, and a manufacturing method thereof wherein the viscosity of a coating solution for an ink receiving layer is low and the dispersion stability thereof is high and which is excellent in productivity. <P>SOLUTION: In the medium for ink jet recording which has the ink receiving layer on a base, the ink receiving layer contains a water-soluble resin and contains at least one or more kinds of organic cationic polymers of which the inorganic/organic properties ratio (I/O value) in an organic conceptual diagram is below 2.8 and at least one or more kinds of organic cationic polymers of which the above ratio is 2.8 or above. In this medium for ink jet recording and the manufacturing method thereof, it is preferable that the ink receiving layer further contains particulates and that the mass content ratio between the organic cationic polymer of which the inorganic/organic properties ratio (I/O value) is below 2.8 and the organic cationic polymer of which the ratio is 2.8 or above is 1:5 to 40:1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is suitable for inkjet recording using liquid inks such as water-based inks (using dyes or pigments as coloring materials) and oil-based inks, or solid inks that are solid at room temperature and melted and liquefied for printing. More particularly, the present invention relates to an inkjet recording medium having excellent ozone resistance and a method for manufacturing the same.

  In recent years, with the rapid development of the information technology (IT) industry, various information processing systems have been developed, and recording methods and recording apparatuses suitable for the information processing systems have been developed and put into practical use. Among these recording methods, the inkjet recording method is capable of recording on a variety of recording materials, has advantages such as being relatively inexpensive and compact in hardware (device), and excellent in quietness. It has also been widely used for so-called home use. In addition, with the recent increase in resolution of inkjet printers, it has become possible to obtain so-called photographic-like high-quality recorded matter. With the progress of such hardware (devices), recording for inkjet recording has become possible. Various seats have been developed.

  The characteristics required for this recording sheet for ink jet recording are generally (1) fast drying (high ink absorption speed), and (2) ink dot diameter is appropriate and uniform. (No blurring), (3) good graininess, (4) high dot roundness, (5) high color density, (6) high chroma (dullness) (7) The water resistance, light resistance, and ozone resistance of the print portion are good, (8) the whiteness of the recording sheet is high, and (9) the storage stability of the recording sheet is good ( Does not cause yellowing coloring even after long-term storage, does not blur images after long-term storage (good aging blur), and (10) is difficult to deform and has good dimensional stability (curl is sufficiently small) (11) Good hard running performance, etc. That. Furthermore, in the use of photo glossy paper used for the purpose of obtaining so-called photographic-like high-quality recorded matter, in addition to the above properties, gloss, surface smoothness, photographic paper-like texture similar to silver salt photography, etc. Is also required.

  In recent years, an ink jet recording medium having a porous structure in the ink receiving layer has been developed and put into practical use for the purpose of improving the various properties described above. Since such an ink jet recording medium has a porous structure, it has excellent ink receptivity (fast drying property) and high gloss.

  For example, there has been proposed an ink jet recording medium containing fine inorganic pigment particles and a water-soluble resin and having an ink receiving layer having a high porosity on a support (for example, see Patent Documents 1 and 2). These recording sheets, in particular, ink jet recording media provided with an ink receiving layer having a porous structure using silica as inorganic pigment fine particles are excellent in ink absorptivity and can form high-resolution images due to their constitution. It has ink-receptive performance and can exhibit high gloss, whereby an image practically comparable to a silver salt photograph can be obtained.

  However, the ink jet recording medium is still insufficient in image storability as compared with silver salt photography, and a significant improvement is desired. Conventionally, with respect to image storability, light resistance related to image degradation due to light has been emphasized, but trace gases in the air, particularly ozone, cause discoloration of recorded images over time. Since the recording material composed of the ink receiving layer having the porous structure described above has a large number of voids, the recorded image is easily faded by ozone gas in the air. For this reason, it is a very important issue for the recording material having the ink receiving layer having the porous structure to improve resistance to ozone in the air (ozone resistance).

  In order to prevent the fading due to ozone, an inkjet recording material containing a sulfinic acid compound, a thiosulfonic acid compound, a thiosulfinic acid compound, or a thiourea compound has been proposed (see Patent Document 3). An ink jet recording material containing a thioether compound having a hydrophilic group has been proposed (see Patent Document 4). Furthermore, a method has been proposed in which a urea derivative, semicarbazide derivative, carbohydrazide derivative, or hydrazine derivative is included in the ink layer (see, for example, Patent Documents 5 and 6). All of these have an effect on ozone resistance, but the effect does not last long, and there is a problem that sufficient ozone resistance cannot be imparted over a long period of time.

  Also disclosed is a recording sheet having a porous ink receiving layer containing one or more compounds selected from the group consisting of dithiocarbamates, thiuram salts, thiocyanates, thiocyanates and hindered amine compounds ( Patent Document 7). Examples of the hindered amine compound include those having a structure in which all hydrogens on carbons at the 2nd and 6th positions of piperidine are substituted with methyl groups, and this recording sheet contains one or more of the above compounds. Thus, although there is an effect of preventing fading for about 30 days indoors, there is still a problem that ozone resistance cannot be imparted over a sufficiently long period.

  In order to further improve ozone resistance, (1) an ink-absorbing layer having an ink absorbing layer that is three-dimensionally cross-linked with a curing agent after mixing a polymer containing a monomer having two types of quaternary ammonium bases Recording material (for example, see Patent Document 8), (2) recording medium having both polyallylamine and a cationic substance having a molecular weight of 1000 or less (for example, see Patent Document 9), (3) water-soluble magnesium salt, N-vinyl Recording medium containing acrylic amidine copolymer and polyamine resin in specific ratio (for example, see Patent Document 10), (4) Cationic polymer compound such as quaternary ammonium methacrylate derivative and alkylamine -Recording paper containing a cationic polymer compound such as epichlorohydrin polymer at a specific cation density (for example, patent documents) 11), (5) a recording sheet for aqueous ink containing a copolymer of (meth) acrylic monomer having a quaternary ammonium salt, N-vinylpyrrolidone and polyamidine (see, for example, Patent Document 12), (6) Inkjet recording paper having an ink absorbing layer containing two or more kinds of cationic polymers (see, for example, Patent Document 13), (7) The outermost layer has a surface layer containing a diallylammonium salt, An ink jet recording medium containing a cationic polymer such as an ink jet recording material containing a cationic polymer (see, for example, Patent Document 14) is disclosed.

However, the stability of fine particle dispersions such as silica is limited, and the present situation is that a cationic polymer that is highly hydrophilic and effective in ozone resistance cannot be fully utilized. In addition to ozone resistance, recent inkjet recording media are required to form images with excellent gloss and high density in order to form photographic-like and high-quality images. However, the dye contained in the ink may reduce the image density, such as causing excessive aggregation depending on the type of mordant combined therewith. Therefore, development of an ink jet recording medium having high fastness to ozone, a high image density, and excellent gloss is desired.
JP 10-119423 A Japanese Patent Laid-Open No. 10-217601 JP 2001-260519 A EP1138509 specification Japanese Patent Laid-Open No. 07-314881 EP1219459 specification JP 07-314882 A Japanese Patent Laid-Open No. 08-14296 Japanese Patent Application Laid-Open No. 07-266689 JP 2000-343813 A JP 2000-272234 A JP 2001-171230 A JP 2001-039026 A JP 2001-315428 A

  The present invention has been made in view of the above circumstances, and the object of the present invention is that the formed image has excellent ozone resistance over a long period of time, and can obtain a high-gloss and high-density image. It is another object of the present invention to provide an ink jet recording medium having a low viscosity of the coating solution, high stability and excellent productivity, and a method for producing the same.

Means of the present invention for solving the above-mentioned problems are as follows.
<1> In an ink jet recording medium having an ink receiving layer on a substrate, the ink receiving layer has a water-soluble resin and an inorganic / organic ratio (I / O value) in an organic conceptual diagram of less than 2.8. An ink jet recording medium comprising at least one organic cationic polymer and at least one organic cationic polymer of 2.8 or more.
<2> The ink jet recording medium according to <1>, wherein the ink receiving layer further contains fine particles.
<3> The mass content ratio of the organic cationic polymer having an inorganic / organic ratio (I / O value) of less than 2.8 and an organic cationic polymer of 2.8 or more is 1: 5 to 40: 1. The ink jet recording medium according to <1> or <2>, wherein the medium is an ink jet recording medium.
<4> The organic cationic polymer having an inorganic / organic ratio (I / O value) of less than 2.8 is an acrylate or methacrylate of dimethyldiallylammonium chloride and a trialkylammonium salt, and an acrylate or trialkylammonium salt. The inkjet recording medium according to any one of <1> to <3>, wherein the medium is at least one selected from the group of methacrylate and styrene copolymers.
<5> The organic cationic polymer having an inorganic / organic ratio (I / O value) of 2.8 or more is polyallylamine, polyethyleneimine, polyvinylamine, polyamidine, dimethylamine-epichlorohydrin polycondensate, and dicyan. -The ink jet recording medium according to any one of <1> to <4>, wherein the medium is at least one selected from the group of diamide-based polycondensates.
<6> The ink jet recording medium according to any one of <1> to <5>, wherein the ink receiving layer contains at least one chelating agent.
<7> The ink jet recording medium according to any one of <1> to <6>, wherein the ink receiving layer contains at least one sulfur-containing compound.
<8> The ink receiving layer is a layer obtained by crosslinking and curing a coating layer on which a coating solution containing at least a water-soluble resin and the two or more organic cationic polymers is coated. And / or adding a cross-linking agent to the following basic solution and (1) applying the coating solution to form a coating layer, or (2) drying the coating layer formed by applying the coating solution. <1> characterized in that it is carried out by applying a basic solution having a pH of 7.1 or higher to the coating layer at any time during the process and before the coating layer exhibits reduced-rate drying. A method for producing an inkjet recording medium according to any one of> to <7>.
<9> An inkjet recording medium manufactured according to the manufacturing method according to claim 8.

  According to the present invention, there is provided an inkjet recording medium capable of obtaining an excellent printed image having a high gloss and a high density, which has good ozone resistance over a long period of time, and a method for producing the same. Can be provided.

  The ink jet recording medium of the present invention is an ink jet recording medium having an ink receiving layer on a substrate, the ink receiving layer is a water-soluble resin, and an inorganic / organic ratio (I / O value) in an organic conceptual diagram. Characterized by containing at least one organic cationic polymer of less than 2.8 and at least one organic cationic polymer of 2.8 or more (hereinafter sometimes referred to as “organic cationic polymer in the present invention”). To do. Further, the ink receiving layer of the present invention preferably has a form containing fine particles, a chelating agent, a sulfur-containing compound and the like.

The ink jet recording medium of the present invention contains the water-soluble resin and the organic cationic polymer as described above in the ink receiving layer, thereby maintaining the ozone resistance of the formed image in a good state over a long period of time. In addition, it is possible to provide a printed image having a high color density and excellent gloss. Furthermore, the ink jet recording medium of the present invention is excellent in water resistance, ink absorbability and the like, can suppress the occurrence of aging blur, and can prevent defects such as cracks.
Hereinafter, the constituents of the ink jet recording medium of the present invention will be described in detail, but the present invention is not limited to these explanatory items, exemplified compounds, and the like.

(Organic cationic polymer of the present invention)
Examples of the organic cationic polymer in the present invention include a cationic polymer having at least one of a primary amino group, a secondary amino group, a tertiary amino group, or a quaternary ammonium base. The organic cationic polymer is preferably a polymer compound having a weight average molecular weight of 500 to 100,000, preferably 800 to 80,000, from the viewpoint of ink absorption performance of the ink receiving layer.

  Specific examples of the organic cationic polymer in the present invention include, for example, trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium. Chloride, N, N-dimethyl-N-ethyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-methyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-Nn- Propyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-Nn-octyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride N, N-diethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N- (4-methyl) benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl -N-phenyl-Np-vinylbenzylammonium chloride;

  Trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-vinylbenzylammonium bromide, trimethyl-p-vinylbenzylammonium sulfonate, trimethyl-m-vinylbenzylammonium sulfonate, trimethyl-p-vinylbenzylammonium acetate, trimethyl-m-vinyl Benzylammonium acetate, N, N, N-triethyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N, N-triethyl-N-2- (3-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride Tate;

  N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N- Methyl chloride, ethyl chloride, methyl bromide of dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide , Quaternized products of ethyl bromide, methyl iodide or ethyl iodide, or polymers and copolymers such as sulfonates, alkylsulfonates, acetates or alkylcarboxylates substituted for their anions Body, and the like.

  More specifically, for example, trimethyl-2- (methacryloyloxy) ethylammonium chloride, triethyl-2- (methacryloyloxy) ethylammonium chloride, trimethyl-2- (acryloyloxy) ethylammonium chloride, triethyl-2- (acryloyl) Oxy) ethylammonium chloride, trimethyl-3- (methacryloyloxy) propylammonium chloride, triethyl-3- (methacryloyloxy) propylammonium chloride, trimethyl-2- (methacryloylamino) ethylammonium chloride, triethyl-2- (methacryloylamino) Ethylammonium chloride, trimethyl-2- (acryloylamino) ethylammonium chloride, triethyl-2 (Acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) propylammonium chloride, triethyl-3- (acryloyl) Amino) propylammonium chloride;

N, N-dimethyl-N-ethyl-2- (methacryloyloxy) ethylammonium chloride, N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium chloride, N, N-dimethyl-N-ethyl- 3- (acryloylamino) propylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium bromide, trimethyl-3- (acryloylamino) propylammonium bromide, trimethyl-2- (methacryloyloxy) ethylammonium sulfonate, trimethyl-3- Examples thereof include polymers and copolymers such as (acryloylamino) propylammonium acetate.
In addition, polymers and copolymers such as N-vinylimidazole and N-vinyl-2-methylimidazole can also be used.

Further, polymers and copolymers such as allylamine, diallylamine, derivatives thereof, and salts can also be used. Examples of such compounds are allylamine, allylamine hydrochloride, allylamine acetate, allylamine sulfate, diallylamine, diallylamine hydrochloride, diallylamine acetate, diallylamine sulfate, diallylmethylamine and salts thereof (for example, Hydrochloride, acetate, sulfate, etc.), diallylethylamine and salts thereof (for example, hydrochloride, acetate, sulfate, etc.), diallyldimethylammonium salt (chloride, acetic acid as counter anions of the salt) And polymers such as ion sulfate ions) and copolymers. In addition, since these allylamines and diallylamine derivatives are inferior in polymerizability in the form of amines, they are generally polymerized in the form of salts and desalted as required.
In addition, a structural unit such as N-vinylacetamide or N-vinylformamide, which is converted into a vinylamine unit by hydrolysis after polymerization, and a salt thereof can also be used.

In the ink receiving layer of the present invention, at least one kind of an organic cationic polymer having an inorganic / organic ratio (I / O value) of less than 2.8 and an organic cationic polymer having a value of 2.8 or more in the organic conceptual diagram is used. Contains above. As the compound that forms such an organic cationic polymer, known compounds can be used.
The above-mentioned inorganic / organic ratio (I / O value) is a parameter representing a measure of the hydrophilicity / lipophilicity of a compound or substituent. “Organic Conceptual Diagram” by Yoshio Koda (Sankyo Publishing, 1984) There is a detailed explanation on it. I represents inorganic and O represents organic. The larger the (I / O) value, the greater the inorganicity (that is, the higher the polarity and the higher the hydrophilicity). The (I / O) value is one of functional group contribution methods for setting parameters for each functional group, and an inorganic value and an organic value are shown for each functional group. For the organic cationic polymer of the present invention, it is necessary to determine the functional group constituting it according to this parameter.
Next, a specific calculation example for the (I / O) value will be described. Typical examples of the I value are 200 for the —NHCO— group, 240 for the —NHSO ₂ — group, and 60 for the —COO— group. For example, in the case of —NHCOC ₅ H _11, the number of carbon atoms is 6, and the O value is 20 × 6 = 120. Since I = 200, I / O≈1.67.

The ink-receiving layer of the present invention contains at least one organic cationic polymer having an inorganic / organic ratio (I / O value) of 2.8 or more, whereby ozone resistance, water resistance, and moisture resistance. Has the effect of improving.
However, if the above (I / O value) is too high, the adsorptivity to the fine particles tends to be poor and the dispersion stability of the fine particles tends to be lowered, and image blurring tends to occur during image storage under high humidity. Therefore, the (I / O value) is preferably at most 2.8 to 10, more preferably 2.8 to 6.0.

Further, the ink receiving layer of the present invention contains at least one organic cationic polymer having an inorganic / organic ratio (I / O value) of less than 2.8. It has the effect of improving the viscosity stability of the liquid.
However, if the (I / O value) is too low, the water solubility becomes poor and the dispersion stability tends to decrease. Therefore, the (I / O value) is preferably at least in the range of 1 to 2.8. A range of 1.8 to 2.8 is more preferable.

The organic cationic polymer used in the present invention may be of any combination as long as it satisfies the above (I / O value).
Organic cationic polymers having an inorganic / organic ratio (I / O value) of 2.8 or more include polyallylamine, polyethyleneimine, polyvinylamine, polyamidine, dimethylamine-epichlorohydrin polycondensate, and dicyan-diamide. Preferred examples include polycondensates. Among these, dimethylamine-epichlorohydrin polycondensate and dicyan-diamide polycondensate are more preferable, and dimethylamine-epichlorohydrin-polyalkylene polyamine polycondensate and dicyandiamide-polyalkylene polyamine polycondensate are particularly preferable. preferable.

  Examples of organic cationic polymers having an inorganic / organic ratio (I / O value) of less than 2.8 include (meth) acrylates of dimethyldiallylammonium chloride, trialkylammonium salts, and (methaacrylates of trialkylammonium salts). Suitable examples include acrylate and styrene copolymers. Among these, a terpolymer of dimethyldiallylammonium chloride, trimethylammonium ethyl methacrylate, and styrene is particularly preferable.

  In the present invention, the organic cationic polymer (a) having an inorganic / organic ratio (I / O value) of less than 2.8 and 2 from the viewpoint of further improving ozone resistance and suitability for production. The mass content ratio (a: b) of the organic cationic polymer (b) of 8 or more is preferably 1: 5 to 40: 1, and the mass content ratio is 1: 2 to 10: 1. Is more preferable, and 1: 1 to 5: 1 is particularly preferable. When the above-mentioned mass content ratio deviates from 1: 5 and the content ratio of the cationic polymer (b) increases, the stability of the coating solution may be lowered and the suitability for production may be impaired, and the mass content ratio may be 40: 1. If the content ratio of the cationic polymer (a) is increased, the effect of improving ozone resistance may be insufficient, which is not preferable.

As the total amount of the cationic polymer in the invention is preferably from ^{0.1g / m 2 ~5g / m 2} , more preferably ^{0.25g / m 2 ~3.5g / m 2} , especially 0.5g / M ^{2 to 2} g / m ² is most preferable. If the amount used is less than 0.1 g / m ² , the improvement in ozone resistance may be insufficient, and if the amount used exceeds 5 g / m ² , the stability of the coating solution will be reduced and produced. Suitability may be impaired, and neither is preferred.

  In the present invention, the method of using the cationic polymer having the above two types (I / O value) is not particularly limited, and various forms are possible according to the purpose and necessity. From the viewpoint of improvement of the dispersion and the stability of the dispersion, it is more preferable that the fine particles such as silica described later and the cationic polymer are present in the same coating solution.

(Chelating agent)
The ink receiving layer of the ink jet recording medium of the present invention preferably contains at least one chelating agent in order to further improve the ozone resistance and the stability of the fine particle dispersion.
The present inventors not only have ozone resistance, but particularly when inorganic fine particles having a primary particle size of 50 nm or less, polyvinyl alcohol having a polymerization degree of 1000 or more, and boric acid are used in particular. It has been found that the coating solution can be made into a low viscosity and stable solution.

As said chelating agent, the compound represented by the following general formula (I) or general formula (II) is preferable.

を表し、ここでＸ¹及びＸ²はそれぞれ独立に酸素原子又はイオウ原子を表し、Ｒ及びＲ¹〜Ｒ³はそれぞれ独立に水素原子、アルキル基、アリール基を表す。Ｒ⁴は置換されていてもよいアルキル基、アリール基、−Ｎ（Ｒ⁵）Ｒ⁶、又は−ＯＲ⁷を表し、ここで該Ｒ⁵とＲ⁶はそれぞれ独立に上記Ｒ¹と同義である。Ｒ⁷はアルキル基又はアリール基を表し、Ｙ¹及びＹ²はそれぞれ独立にアルキレン基又はアリーレン基を表す。尚、上記のＲ、Ｌ¹、Ｌ²は互いに連結して環を形成してもよく、またＲ¹とＲ²も互いに連結して環を形成してもよい。 In the general formula (I), L ¹ and L ² are each independently

Wherein X ¹ and X ² each independently represent an oxygen atom or a sulfur atom, and R and R ^{1 to} R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. R ⁴ represents an optionally substituted alkyl group, aryl group, —N (R ⁵ ) R ⁶ , or —OR ⁷ , wherein R ⁵ and R ⁶ are independently the same as R ¹ above. . R ⁷ represents an alkyl group or an aryl group, and Y ¹ and Y ² each independently represent an alkylene group or an arylene group. R, L ¹ and L ² may be connected to each other to form a ring, and R ¹ and R ² may also be connected to each other to form a ring.

を表し、ここでＸ¹及びＸ²、Ｙ¹及びＹ²、Ｒ¹〜Ｒ⁴はそれぞれ上記一般式（Ｉ）のＸ¹及びＸ²、Ｙ¹及びＹ²、Ｒ¹〜Ｒ⁴とそれぞれ同義である。Ｒ^a〜Ｒ^cはそれぞれ独立に水素原子、アルキル基、アリール基を表し、Ｒ^a〜Ｒ^c及びＬ³は互いに連結して環を形成してもよい。Ｗは２価の連結基を表す。 In the general formula (II), L ³ is

The expressed, wherein X ¹ and X ^2, Y ¹ and Y ^2, R ¹ to R ⁴ X ¹ and X ^2, Y ¹ and Y ² respectively is the general formula (I), R ¹ ~R ^4, respectively It is synonymous. R ^{a to} R ^c each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ^{a to} R ^c and L ³ may be linked to each other to form a ring. W represents a divalent linking group.

  Specific examples of the compounds represented by the above general formula (I) and general formula (II) include, for example, ethylenediaminetetraacetic acid and salts thereof, and B-1 to B-1 described in JP-A-4-73647. Examples thereof include B-79, 1 to 53 described in JP-A No. 6-11805, and salts thereof.

The amount of the chelating agent in the present invention, from the viewpoint of further improving ozone ^{resistance, 0.01g / m 2 ~5g / m} 2 are ^{preferred, 0.05g / m 2 ~3g / m} 2 Gayori preferably, and most preferably ^{0.1g / m 2 ~1g / m 2} . If the amount used is less than 0.01 g / m ² , the effect of improving the ozone resistance may be insufficient, and if the amount used exceeds 5 g / m ² , the stability of the coating solution decreases. However, production suitability may be impaired, and both are not preferable.

(Sulfur-containing compounds)
The ink receiving layer of the ink jet recording medium of the present invention preferably contains at least one sulfur-containing compound in order to further improve ozone resistance.
As a sulfur-containing compound used for this invention, 1 type, or 2 or more types chosen from the compound represented by the following general formula (1)-(4) and (5) is preferable.

In the general formulas (1) to (4), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently have an alkyl group or a substituent which may have a substituent. Represents an aryl group which may be substituted, or a heterocyclic group which may have a substituent, and R ¹ and R ² , R ⁴ and R ⁵ , R ⁶ and R ⁷ are linked to each other to form a ring. Also good.
In general formula (5), X represents a hydroxyl group, a carboxyl group, a carboxylate, an amino group, or a group having one or more of these groups. Y ¹ , Y ² and Y ³ each independently represent an alkylene group. n represents an integer of 1 to 6, and m represents 0 or 1.

In the general formulas (1) to (4), examples of the alkyl group represented by R ^{1 to} R ⁷ include a linear or branched alkyl group. ~ 12 is more preferred. Examples of such alkyl groups are methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, n-pentyl. , N-hexyl group, 2-ethylhexyl group and the like, among which methyl group, ethyl group, n-propyl group and i-propyl group are preferable. In addition, when the alkyl group represented by R ^{1 to} R ⁷ has a substituent, examples of the substituent include a hydroxyl group, a carboxyl group, a sulfonic acid group, and an amino group. preferable.

As an aryl group represented by said R < ¹ > -R < ⁷ >, a C6-C20 thing is preferable and a 6-12 thing is more preferable. Examples of such an aryl group include a phenyl group, a naphthyl group, and an anthranyl group, and among them, a phenyl group is preferable. Further, when the aryl group represented by R ^{1 to} R ⁷ has a substituent, examples of the substituent include a hydroxyl group, a thiol group, a methyl group, a t-butyl group, and the like. Is preferred.

Examples of the heterocyclic group represented by R ^{1 to} R ⁷ include a heterocyclic group containing a nitrogen atom, an oxygen atom, or a sulfur atom, and the total number of carbon, nitrogen, sulfur, and oxygen atoms is as follows. 1-20 are preferable, and 1-12 are more preferable. Examples of such heterocyclic groups are furyl, thienyl, pyridyl, pyrazolyl, isoxazolyl, isothiazolyl, imidazolyl, oxazolyl, thiazolyl, pyridazyl, pyrimidyl, pyrazyl, triazolyl, Preferred examples include tetrazolyl group, quinolyl group, benzothiazolyl group, benzoxazolyl group, benzimidazolyl group, isoquinolyl group, thiadiazolyl group, morpholino group, piperidino group, piperazino group, indolyl group, isoindolyl group and the like. These heterocyclic groups may have a substituent. Examples of the substituent include the same substituents as those of the substituted alkyl group. Among the preferable heterocyclic groups, a furyl group, a thienyl group, a pyridyl group, a morpholino group, a piperidino group, and the like are more preferable.

The compounds represented by the general formulas (1) to (4) are preferably water-soluble, and it is preferable that the compounds are water-soluble because the effects of ozone resistance and light resistance are more easily exhibited. Further, at least one of R ¹ and R ² , at least one of R ⁴ and R ⁵ , or at least one of R ⁶ and R ⁷ has a substituent, and the substituent is Those which are at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a carboxylate, an amino group, a sulfonic acid group, and a sulfonate are preferable, and among them, a hydroxyl group, a carboxyl group, and a carboxylate are particularly preferable.

  Although the preferable specific example of the compound represented by General formula (1)-(4) used for the inkjet recording medium of this invention below is given, this invention is not limited to these examples.

  The inorganic / organic ratio (I / O value) of the compounds represented by the general formulas (1) to (4) is 0.5 or more, and preferably 1.0 to 5.0.

In general formula (5), X represents a hydroxyl group, a carboxyl group, a carboxylate, an amino group, or a group having one or more of these groups. Y ¹ , Y ² and Y ³ each independently represent an alkylene group. n represents an integer of 1 to 6, and m represents 0 or 1.

In the general formula (5), the alkylene group represented by Y ^1, Y ² and Y ^3, preferably 1 to 12 carbon atoms, 1 to 6 carbon atoms is more preferred. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a tetramethylene group, and a hexamethylene group.
In the general formula (5), examples of the group having at least one hydroxyl group, carboxyl group, carboxylate salt, or amino group represented by X include —CH ₂ OH, —CH ₂ COOH, —CH _2. Preferred examples include NH ₂ , —CHOH—CH ₂ OH, CHNH ₂ COOH and the like.

  Specific examples of the thioether compound represented by the general formula (5) used in the inkjet recording medium of the present invention are listed as preferred specific examples of the compounds represented by the general formulas (1) to (4). Among these, 1-16, 1-17, 1-18, 1-21, 1-22, 1-27, 1-95, 1-96, 1-98 and the like can be similarly mentioned.

  The compound represented by the general formula (5) has an I / O value of 0.5 or more, preferably 1.0 to 5.0.

Of the sulfur-containing compounds represented by the general formulas (1) to (5), (1), (2), (4) and (5) are preferable, and (4) and (5) are particularly preferable. The number of sulfur atoms in the molecule is preferably 1 to 6, and particularly preferably 1 to 3.
Furthermore, from the viewpoint of stability of the fine particle dispersion and suppression of aging blur, a high molecular weight polymer having a molecular weight of 1000 or more is preferable, and those having a thioether bond are preferable from the viewpoint of ozone resistance. What is 1.2 meq / g or more is more preferable.

(Water-soluble resin)
The ink receiving layer in the present invention preferably has a porous structure, and preferably comprises a water-soluble resin.
Examples of the water-soluble resin include polyvinyl alcohol resins that are resins having a hydroxy group as a hydrophilic structural unit [polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified. Polyvinyl alcohol, polyvinyl acetal, etc.], cellulosic resins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, etc.] , Chitins, chitosans, starch, resins with ether linkages [polyethylene oxide (PEO), Propylene oxide (PPO), polyethylene glycol (PEG), poly ether (PVE)], and resins having carbamoyl groups [polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like.
In addition, a resin having a carboxyl group as a dissociable group (polyacrylate), a maleic acid resin, an alginate, gelatin, and the like can also be exemplified.

  Among these, polyvinyl alcohol resin is particularly preferable. Examples of the polyvinyl alcohol include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432, Japanese Patent Publication No. 7-29479, Japanese Patent No. 2537827, Japanese Patent Publication No. 7-57553, Japanese Patent No. 2502998, and Japanese Patent No. 3053231. JP-A-63-176173, JP-A-2604367, JP-A-7-276787, JP-A-9-207425, JP-A-11-58941, JP-A-2000-135858, JP-A-2001-205924, JP 2001-287444, JP 62-278080, JP 9-39373, JP 2750433, JP 2000-18801, JP 2001-213045, JP 2001-328345, JP 8 -324105, JP-A-11-348417, etc. It is below.

  Examples of other water-soluble resins other than the polyvinyl alcohol-based resin include compounds described in [0173] to [0174] of JP-A No. 11-165461. These water-soluble resins may be used alone or in combination of two or more.

  In addition, the polyvinyl alcohol-based resin may be used in combination with the other water-soluble resins. When the other water-soluble resin and the polyvinyl alcohol resin are used in combination, the content of the polyvinyl alcohol resin in the total water-soluble resin is preferably 50% by mass or more, and more preferably 70% by mass or more.

  In the present invention, the content of the water-soluble resin is preferably 9 to 40% by mass, and more preferably 12 to 33% by mass with respect to the total solid mass of the ink receiving layer.

(Fine particles)
In the ink jet recording medium of the present invention, the ink receiving layer preferably contains fine particles, and it is more preferred to use the fine particles and the water-soluble resin in combination. When the ink receiving layer contains fine particles, a porous structure can be obtained, thereby improving the ink absorption performance. In particular, when the solid content in the ink-receiving layer of the fine particles is 50% by mass or more, more preferably more than 60% by mass, it becomes possible to form a better porous structure, and sufficient ink absorptivity. An ink jet recording medium having the above is obtained. Here, the solid content in the ink receiving layer of fine particles is a content calculated based on components other than water in the composition constituting the ink receiving layer.

As the fine particles, organic fine particles and inorganic fine particles can be used, but it is preferable to contain inorganic fine particles from the viewpoint of ink absorbability and image stability.
The organic fine particles are preferably polymer fine particles obtained by, for example, emulsion polymerization, microemulsion polymerization, soap-free polymerization, seed polymerization, dispersion polymerization, suspension polymerization, and the like. Polyethylene, polypropylene, polystyrene, polyacrylate, polyamide, silicon resin , Phenol resin, natural polymer powder, latex or emulsion polymer fine particles, and the like.

Examples of the inorganic fine particles include silica fine particles, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, pseudoboehmite, zinc oxide, water. Examples thereof include zinc oxide, alumina, aluminum silicate, calcium silicate, magnesium silicate, zirconium oxide, zirconium hydroxide, cerium oxide, lanthanum oxide, and yttrium oxide. Among these, silica fine particles, colloidal silica, alumina fine particles, or pseudoboehmite are preferable from the viewpoint of forming a good porous structure. The fine particles may be used as primary particles or in a state where secondary particles are formed. The average primary particle size of these fine particles is preferably 2 μm or less, more preferably 200 nm or less.
Further, silica fine particles having an average primary particle size of 20 nm or less, colloidal silica having an average primary particle size of 30 nm or less, alumina fine particles having an average primary particle size of 20 nm or less, or pseudoboehmite having an average pore radius of 2 to 15 nm is more preferable. In particular, silica fine particles, alumina fine particles, and pseudoboehmite are preferable.

  Silica fine particles are generally roughly classified into wet method particles and dry method (gas phase method) particles according to the production method. In the above wet method, a method is mainly used in which activated silica is produced by acid decomposition of a silicate, and this is appropriately polymerized and agglomerated and precipitated to obtain hydrous silica. On the other hand, the gas phase method is a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method), a method in which silica sand and coke are heated and reduced by an arc in an electric furnace and oxidized with air. The method of obtaining anhydrous silica by the (arc method) is the mainstream, and “gas phase method silica” means anhydrous silica fine particles obtained by the gas phase method. As the silica fine particles used in the present invention, gas phase method silica fine particles are particularly preferable.

The gas phase method silica is different from hydrous silica in terms of the density of silanol groups on the surface, the presence or absence of vacancies, etc., and exhibits different properties, but is suitable for forming a three-dimensional structure with a high porosity. The reason for this is not clear, but in the case of hydrous silica, the density of silanol groups on the fine particle surface is high at 5 to 8 / nm ² , and the silica fine particles tend to aggregate (aggregate) easily. In the case of the method silica, the density of silanol groups on the surface of the fine particles is 2 to 3 / nm ² , so that it is sparse soft agglomeration (flocculate), resulting in a structure with a high porosity. Is done.

  The above-mentioned vapor phase silica has a particularly large specific surface area, so the ink absorption and retention efficiency is high, and the refractive index is low. Therefore, if the dispersion is made to an appropriate particle size, transparency can be imparted to the receiving layer. It is characterized by high color density and good color development. The transparency of the receiving layer is not only for applications that require transparency such as OHP, but also when applied to recording media such as photo glossy paper, from the viewpoint of obtaining high color density and good color development gloss Is important.

  The average primary particle diameter of the vapor phase silica is preferably 30 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, and most preferably 3 to 10 nm. Since the vapor phase silica is easily adhered to each other by hydrogen bonding with a silanol group, a structure having a large porosity can be formed when the average primary particle diameter is 30 nm or less, and ink absorption characteristics are effectively improved. Can be improved.

  Silica fine particles may be used in combination with the other fine particles described above. When the other fine particles and the vapor phase silica are used in combination, the content of the vapor phase silica in all the fine particles is preferably 30% by mass or more, and more preferably 50% by mass or more.

As the inorganic fine particles in the present invention, alumina fine particles, alumina hydrate, a mixture or a composite thereof are also preferable. Of these, alumina hydrate is preferable because it absorbs and fixes ink well, and pseudoboehmite (Al ₂ O ₃ .nH ₂ O) is particularly preferable. Alumina hydrates can be used in various forms, but it is preferable to use sol boehmite as a raw material because a smooth layer can be easily obtained.

About the pore structure of pseudo boehmite, the average pore radius is preferably 1 to 30 nm, and more preferably 2 to 15 nm. The pore volume is preferably 0.3 to 2.0 ml / g (cc / g), and more preferably 0.5 to 1.5 ml / g (cc / g). Here, the pore radius and pore volume are measured by a nitrogen adsorption / desorption method, and can be measured by, for example, a gas adsorption / desorption analyzer (for example, trade name “Omni Soap 369” manufactured by Coulter). .
Among alumina fine particles, vapor-phase method alumina fine particles are preferable because of their large specific surface area. The average primary particle size of the vapor phase alumina is preferably 30 nm or less, and more preferably 20 nm or less.

  When the above-mentioned fine particles are used in an inkjet recording medium, for example, JP-A-10-81064, JP-A-10-119423, JP-A-10-157277, JP-A-10-217601, JP-A-11-348409, JP-A-2001-2001. 138621, 2000-43401, 2000-21235, 2000-309157, 2001-96897, 2001-138627, JP-A-11-91242, 8-2087, 8-2090 No. 8-2091, No. 8-2093, No. 8-174992, No. 11-192777, JP-A No. 2001-301314, etc. can be preferably used.

The fine particles mainly constituting the porous structure of the ink receiving layer in the present invention may be a single material or a mixed system of a plurality of materials.
From the viewpoint of maintaining transparency, the type of water-soluble resin to be combined with fine particles, particularly silica fine particles, is important. When the vapor phase silica is used, the water-soluble resin is preferably a polyvinyl alcohol resin, more preferably a polyvinyl alcohol resin having a saponification degree of 70 to 100%, and a saponification degree of 80 to 99.5. % Of polyvinyl alcohol resin is particularly preferable.

The polyvinyl alcohol-based resin has a hydroxyl group in the structural unit, and since the hydroxyl group and the surface silanol group of the silica fine particle form a hydrogen bond, a three-dimensional network having a secondary particle of the silica fine particle as a network chain unit. It becomes easy to form a structure. By forming this three-dimensional network structure, it is considered that a porous ink receiving layer having a high porosity and sufficient strength is formed.
In ink jet recording, the porous ink receiving layer obtained as described above can absorb ink rapidly by a capillary phenomenon, and can form dots with good roundness without ink bleeding.

(Content ratio of fine particles to water-soluble resin)
The mass content ratio of the fine particles (x) and the water-soluble resin (y) [PB ratio (x: y)] has a great influence on the film structure and film strength of the ink receiving layer. That is, as the mass content ratio [PB ratio] increases, the porosity, pore volume, and surface area (per unit mass) increase, but the density and strength tend to decrease.

  The ink receiving layer according to the present invention has the above mass content ratio [PB ratio (x: y)], which prevents a decrease in film strength and cracks during drying caused by the PB ratio being too large, and When the PB ratio is too small, the voids are easily blocked by the resin, and from the viewpoint of preventing the ink absorbency from being lowered due to the decrease in the void ratio, 1.5: 1 to 10: 1 is preferable. .

  Since stress may be applied to the recording medium when passing through the transport system of the ink jet printer, the ink receiving layer needs to have sufficient film strength. Further, when cutting into a sheet shape, the ink receiving layer needs to have sufficient film strength in order to prevent cracking or peeling of the ink receiving layer. In consideration of these cases, the mass ratio (x: y) is more preferably 5: 1 or less, while it is more preferably 2: 1 or more from the viewpoint of ensuring high-speed ink absorbability in an inkjet printer. preferable.

For example, a coating solution in which gas phase method silica fine particles having an average primary particle diameter of 20 nm or less and a water-soluble resin are completely dispersed in an aqueous solution at a mass ratio (x: y) of 2: 1 to 5: 1 is provided on the support. When the coating layer is dried, a three-dimensional network structure in which secondary particles of silica fine particles are network chains is formed, the average pore diameter is 30 nm or less, the porosity is 50 to 80%, the pore ratio A translucent porous film having a volume of 0.5 ml / g or more and a specific surface area of 100 m ² / g or more can be easily formed.

(Crosslinking agent)
The ink-receiving layer in the invention preferably contains a crosslinking agent that can further crosslink the water-soluble resin in the coating layer containing the water-soluble resin. In particular, the fine particles and the water-soluble resin are used in combination. An embodiment having a porous structure in which a water-soluble resin is cured by crosslinking reaction with an agent is preferable.

Boron compounds are preferred for the crosslinking of the water-soluble resin, particularly polyvinyl alcohol. Examples of the boron compound include borax, boric acid, borate (for example, orthoborate, InBO ₃ , ScBO ₃ , YBO ₃ , LaBO ₃ , Mg ₃ (BO ₃ ) ₂ , Co ₃ (BO ₃ ) ₂ , two Borate (eg, Mg ₂ B ₂ O ₅ , Co ₂ B ₂ O ₅ ), metaborate (eg, LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ , KBO ₂ ), tetraborate (eg, Na _{2 B 4 O 7 · 10H 2} O), can be mentioned five borate _{(e.g., KB 5 O 8 · 4H 2} O, Ca 2 B 6 O 11 · 7H 2 O, CsB 5 O 5) or the like. Among them, Of these, borax, boric acid, and borate are preferable, and boric acid is particularly preferable in that a crosslinking reaction can be promptly caused.

The following compounds other than the boron compound can also be used as a crosslinking agent for the water-soluble resin.
For example, aldehyde compounds such as formaldehyde, glyoxal, and glutaraldehyde; ketone compounds such as diacetyl and cyclopentanedione; bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1,3,5- Active halogen compounds such as triazine and 2,4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide) ), Active vinyl compounds such as 1,3,5-triacryloyl-hexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin; melamine resins (for example, methylolmelamine, alkylated methylolmelamine) ;

Isocyanate compounds such as epoxy resins and 1,6-hexamethylene diisocyanate; aziridine compounds described in US Pat. Nos. 3,017,280 and 2,983611; carboximide compounds described in US Pat. No. 3,100,704; Epoxy compounds such as glycerol triglycidyl ether; ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; Dioxane compounds such as 3-dihydroxydioxane; metal-containing compounds such as titanium lactate, aluminum sulfate, chromium alum, potash alum, zirconyl acetate and chromium acetate, polyamine compounds such as tetraethylenepentamine, and hydrides such as adipic acid dihydrazide Examples thereof include a razide compound and a low molecule or polymer containing two or more oxazoline groups.
Said crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the crosslinking agent used is preferably from 1 to 50% by weight, more preferably from 5 to 40% by weight, based on the water-soluble resin.

In the present invention, the cross-linking curing is performed by crosslinking into a coating solution (hereinafter sometimes referred to as “coating solution A”) containing at least a water-soluble resin and the two or more organic cationic polymers and / or the following basic solution. And (1) simultaneously with forming the coating layer by applying the coating solution, or (2) during the drying of the coating layer formed by coating the coating solution, It is preferably carried out by applying a basic solution having a pH of 7.1 or higher (hereinafter sometimes referred to as “coating liquid B”) to the coating layer at any time before exhibiting reduced-rate drying. .
The application of the crosslinking agent is preferably carried out as follows, taking a boron compound as an example. That is, when the ink receiving layer is a layer obtained by crosslinking and curing a coating layer coated with a coating solution (coating solution A) containing a water-soluble resin (polyvinyl alcohol) and the two or more organic cationic polymers, Crosslinking and curing are (1) when the above coating solution is applied to form a coating layer, and (2) during the dry coating of the coating layer formed by coating the coating solution, and the coating layer is dried at a reduced rate. Is performed by applying a basic solution (coating solution B) having a pH of 7.1 or higher to the coating layer. Here, the boron compound as the crosslinking agent may be contained in either the coating liquid A or the coating liquid B, and may be contained in both the coating liquid A and the coating liquid B.

(mordant)
In the present invention, in combination with the cationic polymer of the present invention, in order to improve the water resistance and aging resistance of the formed image, a polymer mordant (for example, quaternary ammonium) other than the cationic polymer is used in the ink receiving layer. A polymer having a salt or the like) or an inorganic mordant (hereinafter, these may be collectively referred to as “other mordants”). The organic mordant and inorganic mordant may be used alone or in combination with an organic mordant and an inorganic mordant.
When the cationic polymer and other mordants in the present invention are used in combination, the ratio may be determined in consideration of the balance between preservability and aging blurring. Among the mordants used at that time, the cationic property in the present invention The mass ratio of the polymer is preferably 10% or more, preferably 20% or more.

  When the mordant containing the cationic polymer in the present invention is applied to the ink receiving layer, there is a concern that aggregation may occur between the fine particles and the coating solution A containing the water-soluble resin or fine particles. In such a case, a method of coating the coating liquid B can be used.

  Specific examples of the polymer mordant that can be used in combination with the cationic polymer in the present invention include JP-A Nos. 48-28325, 54-74430, 54-124726, 55-22766, and 55-142339. 60-23850, 60-23835, 60-23852, 60-23835, 60-57836, 60-60643, 60-118834, 60-122940, 60-122941, 60-122942, 60-235134, JP-A-1-161236, U.S. Pat. Nos. 2,484,430, 2,548,564, 3,148,061, 3,309,690, 4,115,124, 4,124,386 , 4193800, 4273853, 4282305, 4450224, JP-A-1-161236, 10-81064, 10-119423, 10-157277, 10-217601, 11-348409, JP-A-2001-138621, 2000- 43401, 2000-21235, 2000-309157, 2001-96897, 2001-138627, JP-A-11-91242, 8-2087, 8-2090, 8-2091 No. 8-2093, No. 8-174992, No. 11-192777, JP-A No. 2001-301314, Japanese Patent Publication No. 5-35162, No. 5-35163, No. 5-35164, No. 5-88846. No. 7, JP-A-7-118333, JP-A 2000-344990, and Japanese Patent No. 2648847 Such as those described in each publication of such Nos. 2661677 and the like.

Examples of the inorganic mordant that can be used in combination with the cationic polymer in the present invention include polyvalent water-soluble metal salts and hydrophobic metal salt compounds.
Specific examples of the inorganic mordant include, for example, magnesium, aluminum, calcium, scandium, titanium, vanadium, manganese, iron, nickel, copper, zinc, gallium, germanium, strontium, yttrium, zirconium, molybdenum, indium, barium, lanthanum, Examples include salts or complexes of metals selected from cerium, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, erbium, ytterbium, hafnium, tungsten, bismuth.

  Specifically, for example, calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, manganese ammonium sulfate hexahydrate, chloride chloride Dicopper, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel sulfate Ammonium hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum alum, basic polyaluminum hydroxide, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate , Ferrous bromide, ferrous chloride, ferric chloride Ferrous sulfate, ferric sulfate, zinc phenolsulfonate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate, titanium tetrachloride, tetraisopropyl titanate, titanium acetylacetonate, titanium lactate, zirconium acetyl Acetonate, zirconyl acetate, zirconyl sulfate, ammonium zirconium carbonate, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconium oxychloride, zirconium zirconium chloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, citric acid Magnesium nonahydrate, sodium phosphotungstate, sodium tungsten citrate, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphoric acid n hydrate, gallium nitrate , Strontium nitrate, yttrium acetate, yttrium chloride, yttrium nitrate, indium nitrate, lanthanum nitrate, lanthanum chloride, lanthanum acetate, lanthanum benzoate, cerium chloride, cerium sulfate, cerium octylate, praseodymium nitrate, neodymium nitrate, nitric acid Examples include samarium, europium nitrate, gadolinium nitrate, dysprosium nitrate, erbium nitrate, ytterbium nitrate, hafnium chloride, and bismuth nitrate.

In the present invention, the inorganic mordant is preferably an aluminum-containing compound, a titanium-containing compound, a zirconium-containing compound, or a metal compound (salt or complex) of Group IIIB of the Periodic Table of Elements, particularly an aluminum-containing compound or a zirconium-containing compound. preferable.
Further, the above aluminum-containing compounds include water-soluble aluminum compounds (aluminum sulfate, aluminum alum, basic polyaluminum hydroxide, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate. The zirconium-containing compound is preferably a water-soluble zirconium compound (such as zirconyl acetate, zirconyl sulfate, ammonium zirconium carbonate, zirconyl nitrate, zirconium oxychloride, and zirconium zirconium hydroxychloride). Among these, basic polyaluminum hydroxide is particularly preferable.

Total mordant content in the ink receiving layer in the present invention is preferably from ^{0.01g / m 2 ~5g / m 2} , 0.1g / m 2 ~3g / m 2 is more preferable. In the case where an inorganic mordant and an organic mordant are used in combination, the ratio may be determined based on a balance between storage stability and blemishes, and among the mordants used at that time, the ratio of the inorganic mordant is 5% or more, preferably 10 % Or more is preferable.

(Other ingredients)
The ink jet recording medium of the present invention may be further added with various known additives such as acids, ultraviolet absorbers, antioxidants, fluorescent brighteners, monomers, polymerization initiators, polymerization inhibitors, depending on the purpose and necessity. , Anti-bleeding agents, preservatives, viscosity stabilizers, antifoaming agents, surfactants, antistatic agents, matting agents, anti-curling agents, water-proofing agents, and the like.

  In the present invention, the ink receiving layer may contain an acid. By adding an acid, the surface pH of the ink receiving layer is adjusted to 3 to 8, preferably 5 to 7.5. This is preferable because yellowing resistance of the white background portion is improved. The surface pH is measured by the A method (coating method) in the surface pH measurement determined by the Japan Paper Pulp Technology Association (J.TAPPI). For example, the measurement can be performed using a pH measurement set for paper “model MPC” manufactured by Kyoritsu Riken Co., Ltd., which corresponds to the method A.

Specific examples of acids include formic acid, acetic acid, glycolic acid, oxalic acid, propionic acid, malonic acid, succinic acid, adipic acid, maleic acid, malic acid, tartaric acid, citric acid, benzoic acid, phthalic acid, isophthalic acid , Glutaric acid, gluconic acid, lactic acid, aspartic acid, glutamic acid, salicylic acid, salicylic acid metal salts (Zn, Al, Ca, Mg, etc.), methanesulfonic acid, itaconic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfone Acid, styrenesulfonic acid, trifluoroacetic acid, barbituric acid, acrylic acid, methacrylic acid, cinnamic acid, 4-hydroxybenzoic acid, aminobenzoic acid, naphthalenedisulfonic acid, hydroxybenzenesulfonic acid, toluenesulfinic acid, benzenesulfinic acid, Sulfanilic acid, sulfamic acid, α-le Examples include ricinic acid, β-resorcinic acid, γ-resorcinic acid, gallic acid, phloroglicin, sulfosalicylic acid, ascorbic acid, erythorbic acid, bisphenolic acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, boric acid, boronic acid, etc. It is done. The amount of these acids added may be determined so that the surface PH of the ink receiving layer is 3-8.
The above acids can be metal salts (eg, sodium, potassium, calcium, cesium, zinc, copper, iron, aluminum, zirconium, lanthanum, yttrium, magnesium, strontium, cerium, etc.) or amine salts (eg, ammonia, triethylamine, tri Butylamine, piperazine, 2-methylpiperazine, polyallylamine, etc.).

In the present invention, the ink receiving layer may contain a storage stability improver such as an ultraviolet absorber, an antioxidant, or a bleeding inhibitor.
These ultraviolet absorbers, antioxidants and anti-bleeding agents include alkylated phenol compounds (including hindered phenol compounds), alkylthiomethylphenol compounds, hydroquinone compounds, alkylated hydroquinone compounds, tocopherol compounds, thiodiphenyl ether compounds, 2 Compounds having the above thioether bonds, bisphenol compounds, O-, N- and S-benzyl compounds, hydroxybenzyl compounds, triazine compounds, phosphonate compounds, acylaminophenol compounds, ester compounds, amide compounds, ascorbic acid, amine antioxidants Agent, 2- (2-hydroxyphenyl) benzotriazole compound, 2-hydroxybenzophenone compound, acrylate, water-soluble or hydrophobic metal salt, organometallic compound, metal complex Hindered amine compounds (including TEMPO compounds), 2- (2-hydroxyphenyl) 1,3,5, -triazine compounds, metal deactivators, phosphite compounds, phosphonite compounds, hydroxyamine compounds, nitrone compounds, peroxides Scavenger, polyamide stabilizer, polyether compound, basic auxiliary stabilizer, nucleating agent, benzofuranone compound, indolinone compound, phosphine compound, polyamine compound, thiourea compound, urea compound, hydrazide compound, amidine compound, sugar compound, hydroxybenzoic acid A compound, a dihydroxybenzoic acid compound, a trihydroxybenzoic acid compound, and the like.

  Among these, alkylated phenol compounds, compounds having two or more thioether bonds, bisphenol compounds, ascorbic acid, amine-based antioxidants, water-soluble or hydrophobic metal salts, organometallic compounds, metal complexes, hindered amine compounds, Hydroxyamine compounds, polyamine compounds, thiourea compounds, hydrazide compounds, hydroxybenzoic acid compounds, dihydroxybenzoic acid compounds, trihydroxybenzoic acid compounds and the like are preferable.

  Specific examples of the compound include Japanese Patent Application No. 2002-13005, Japanese Patent Application Laid-Open No. 10-182621, Japanese Patent Application Laid-Open No. 2001-260519, Japanese Patent Application No. 4-34953, Japanese Patent Application No. 4-34513, Japanese Patent Application Laid-Open No. 11-170686, No. 4-34512, EP 1138509, JP-A-60-67190, JP-A-7-276808, JP-A-2001-94829, JP-A-47-10537, JP-A-58-111942, and JP-A-58-212844. 59-19945, 59-46646, 59-109055, 63-53544, JP 36-10466, 42-26187, 48-30492, 48-31255, 48-41572, 48-54965, 50-10726, U.S. Pat.No. 2,719,086, 3 No. 707,375, the 3,754,919 Patent, Nos. 4,220,711;

  Japanese Patent Publication Nos. 45-4699, 54-5324, European Published Patent Nos. 223739, 309401, 309402, 3105301, 310552, 457416, German Published Patent No. 3435443, Kaisho 54-48535, 60-107384, 60-107383, 60-125470, 60-125471, 60-125472, 60-287485, 60-287486, 60-287487, 60-287488, 61-160287, 61-18854, 61-2111079, 62-146678, 62-146680, 62-146679, 62- No. 282885, No. 62-262047, No. 63-051174, Nos. 63-89877, 63-88380 same issue, same 66-88381 JP, Nos. 63-113536;

  63-163351, 63-203372, 63-224989, 63-251282, 63-267594, 63-182484, JP-A-1-239282, JP-A-2-262654, 2-71262, 3-121449, 4-291865, 4-291684, 5-611166, 5-119449, 5-188687, 5-188686, 5 No. 110490, No. 5-110437, No. 5-170361, No. 48-43295, No. 48-33212, US Pat. Nos. 4,814,262, No. 4,980,275, and the like. .

These other components may be used alone or in combination of two or more. The other components may be added after being water-solubilized, dispersed, polymer-dispersed, emulsified, or oil-dropped, or may be encapsulated in microcapsules. The amount of the other components, 0.01 to 10 g / m ² is preferred.

  Further, the surface of the inorganic fine particles may be treated with a silane coupling agent for the purpose of improving the dispersibility of the inorganic fine particles. Examples of the silane coupling agent include an organic functional group (for example, vinyl group, amino group (primary to tertiary amino group, quaternary ammonium base), epoxy group, mercapto, in addition to the site for coupling treatment. Group, chloro group, alkyl group, phenyl group, ester group, etc.)

In the present invention, the ink receiving layer coating solution preferably contains a surfactant. As the surfactant, any of nonionic, amphoteric, anionic, cationic, fluorine, and silicon surfactants can be used.
Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers and polyoxyalkylene alkyl phenyl ethers (for example, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene Ethylene nonylphenyl ether), oxyethylene / oxypropylene block copolymer, sorbitan fatty acid esters (for example, sorbitan monolaurate, sorbitan monooleate, sorbitan trioleate, etc.), polyoxyethylene sorbitan fatty acid esters (for example, polyoxyethylene) Sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitant Oleate, etc.), polyoxyethylene sorbitol fatty acid esters (eg, polyoxyethylene sorbitol tetraoleate), glycerin fatty acid esters (eg, glycerol monooleate), polyoxyethylene glycerin fatty acid esters (polyoxymonostearate) Ethylene glycerol, monooleic acid polyoxyethylene glycerin, etc.), polyoxyethylene fatty acid esters (polyethylene glycol monolaurate, polyethylene glycol monooleate, etc.), polyoxyethylene alkylamine, acetylene glycols (eg, 2, 4, 7) , 9-tetramethyl-5-decyne-4,7-diol, and ethylene oxide adducts and propylene oxide adducts of the diols), and the like. Sharp emission alkyl ethers are preferable. The nonionic surfactant can be used in the first coating solution and the second coating solution. Moreover, the said nonionic surfactant may be used independently and may use 2 or more types together.

  Examples of the amphoteric surfactant include amino acid type, carboxyammonium betaine type, sulfoammonium betaine type, ammonium sulfate betaine type, imidazolium betaine type and the like. For example, US Pat. No. 3,843,368, JP, JP-A-59-49535, JP-A-63-236546, JP-A-5-303205, JP-A-8-262742, JP-A-10-282619, JP-A-2514194, JP-A-2759597, JP-A-2000-351269, etc. Can be used preferably. Of the amphoteric surfactants, the amino acid type, carboxyammonium betaine type, and sulfoneammonium betaine type are preferable. The amphoteric surfactants may be used alone or in combination of two or more.

Examples of the anionic surfactant include fatty acid salts (eg, sodium stearate, potassium oleate), alkyl sulfate esters (eg, sodium lauryl sulfate, triethanolamine lauryl sulfate), and sulfonates (eg, sodium dodecylbenzene sulfonate). Alkyl sulfosuccinate (for example, sodium dioctyl sulfosuccinate), alkyl diphenyl ether disulfonate, alkyl phosphate, and the like.
Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, pyridinium salts, imidazolium salts, and the like.

  Examples of the fluorosurfactant include compounds derived from an intermediate having a perfluoroalkyl group using methods such as electrolytic fluorination, telomerization, and oligomerization. For example, perfluoroalkyl Examples include sulfonates, perfluoroalkyl carboxylates, perfluoroalkylethylene oxide adducts, perfluoroalkyltrialkylammonium salts, perfluoroalkyl group-containing oligomers, and perfluoroalkyl phosphates.

  As the silicon-based surfactant, silicon oil modified with an organic group is preferable, and a structure in which a side chain of a siloxane structure is modified with an organic group, a structure in which both ends are modified, and a structure in which one end is modified can be taken. Examples of the organic group modification include amino modification, polyether modification, epoxy modification, carboxyl modification, carbinol modification, alkyl modification, aralkyl modification, phenol modification, and fluorine modification.

  In the present invention, the content of the surfactant is preferably 0.001 to 2.0%, more preferably 0.01 to 1.0%, with respect to the ink receiving layer coating solution. Further, when coating is performed using two or more liquids as the ink receiving layer coating liquid, it is preferable to add a surfactant to each coating liquid.

  In the present invention, the ink receiving layer preferably contains a high boiling point organic solvent for curling prevention. The high-boiling organic solvent is an organic compound having a boiling point of 150 ° C. or higher at normal pressure, and is a water-soluble or hydrophobic compound. These may be liquid or solid at room temperature, and may be low molecules or polymers.

  Specific examples of the high-boiling organic solvent include aromatic carboxylic acid esters (for example, dibutyl phthalate, diphenyl phthalate, phenyl benzoate, etc.), aliphatic carboxylic acid esters (for example, dioctyl adipate, dibutyl sebacate, Methyl stearate, dibutyl maleate, dibutyl fumarate, triethyl acetylcitrate, etc.), phosphate esters (eg trioctyl phosphate, tricresyl phosphate etc.), epoxies (eg epoxidized soybean oil, epoxidized fatty acid methyl, etc.) Alcohols (eg, stearyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, glycerin, diethylene glycol monobutyl ether (DEGMBE), triethylene glycol monobutyl) Ether, glycerol monomethyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol, 1,2,6-hexanetriol, thiodiglycol, triethanolamine, Polyethylene glycol, etc.), vegetable oils (eg, soybean oil, sunflower oil, etc.) and higher aliphatic carboxylic acids (eg, linoleic acid, oleic acid, etc.).

(Support)
As the substrate used in the ink jet recording medium of the present invention, either a transparent support made of a transparent material such as plastic or an opaque support made of an opaque material such as paper can be used. In order to make use of the transparency of the ink receiving layer, it is preferable to use a transparent support or a highly glossy opaque support.

The material that can be used for the transparent support is preferably a material that is transparent and can withstand radiant heat when used in an OHP or a backlight display. Examples of the material include polyesters such as polyethylene terephthalate (PET); polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide and the like. Of these, polyesters are preferable, and polyethylene terephthalate is particularly preferable.
Although there is no restriction | limiting in particular as thickness of the said transparent support body, 50-200 micrometers is preferable at the point which is easy to handle.

  As the highly glossy opaque support, one having a glossiness of 40% or more on the surface on which the ink receiving layer is provided is preferable. The glossiness is a value determined according to the method described in JIS P-8142 (75-degree specular gloss test method for paper and paperboard). Specifically, the following supports are mentioned.

  Examples of the high-gloss opaque support include, for example, high-gloss paper support such as art paper, coated paper, cast-coated paper, and baryta paper used for silver salt photographic support; polyethylene terephthalate (PET) Such as polyesters such as nitrocellulose, cellulose acetate, cellulose acetate such as cellulose acetate butyrate, and plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide, etc. are made opaque by adding white pigments (surface calendar treatment) High gloss film; or the surface of the high gloss film containing the above various paper supports, the above transparent support or the white pigment or the like, or not containing a white pigment. Support with a coating layer of polyolefin And the like.

  Further, as the highly glossy opaque support, a white pigment-containing foamed polyester film (for example, foamed PET containing polyolefin fine particles and forming voids by stretching) can also be suitably exemplified. Resin-coated paper used for silver salt photographic printing paper is also suitable.

  Although there is no restriction | limiting in particular also about the thickness of the said opaque support body, 50-300 micrometers is preferable at the point of handleability.

  The surface of the support may be subjected to corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment or the like in order to improve wettability and adhesion.

Next, the base paper used for the resin-coated paper will be described in detail.
The base paper is made from wood pulp as a main raw material and, if necessary, paper using synthetic pulp such as polypropylene or synthetic fibers such as nylon or polyester in addition to wood pulp. As the wood pulp, any of LBKP, LBSP, NBKP, NBSP, LDP, NDP, LUKP, and NUKP can be used, but more LBKP, NBSP, LBSP, NDP, and LDP with a larger amount of short fibers are used. preferable.
However, the ratio of LBSP and / or LDP is preferably 10% by mass or more and 70% by mass or less.

  The pulp is preferably a chemical pulp (sulfate pulp or sulfite pulp) with few impurities, and a pulp having a whiteness improved by bleaching is also useful.

  In the base paper, sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength enhancing agents such as starch, polyacrylamide and polyvinyl alcohol, fluorescent whitening agents, polyethylene glycols A water retaining agent such as a dispersant, a softening agent such as a quaternary ammonium, and the like can be appropriately added.

  The freeness of the pulp used for papermaking is preferably 200 to 500 ml as defined by CSF, and the fiber length after beating is a 24 mesh residual mass% and a 42 mesh residual as defined in JIS P-8207. It is preferable that the sum with the mass% of is 30 to 70%. In addition, it is preferable that the mass% of 4 mesh remainder is 20 mass% or less.

The basis weight of the base paper is preferably 30 to 250 g, and particularly preferably 50 to 200 g. The thickness of the base paper is preferably 40 to 250 μm. The base paper can be given a high smoothness by calendering at the paper making stage or after paper making. The density of the base paper is generally 0.7 to 1.2 g / m ₂ (JIS P-8118).
Furthermore, the base paper stiffness is preferably 20 to 200 g under the conditions specified in JIS P-8143.

A surface sizing agent may be applied to the surface of the base paper. As the surface sizing agent, a sizing agent similar to the size that can be added to the base paper can be used.
The pH of the base paper is preferably 5 to 9 when measured by a hot water extraction method defined in JIS P-8113.

  The polyethylene covering the front and back surfaces of the base paper is mainly low-density polyethylene (LDPE) and / or high-density polyethylene (HDPE), but some other LLDPE, polypropylene, etc. can also be used.

  In particular, the polyethylene layer on the side that forms the ink receiving layer is added with rutile or anatase type titanium oxide, fluorescent whitening agent, ultramarine, and polyethylene, as is widely done in photographic paper. Those having improved whiteness and hue are preferred. Here, as titanium oxide content, 3-20 mass% is preferable with respect to polyethylene, and 4-13 mass% is still more preferable. Although the thickness of a polyethylene layer does not have limitation in particular, 10-50 micrometers is suitable for both front and back layers. Further, an undercoat layer can be provided on the polyethylene layer in order to provide adhesion to the ink receiving layer. As the undercoat layer, aqueous polyester, gelatin and PVA are preferable. Moreover, as thickness of this undercoat layer, 0.01-5 micrometers is preferable.

  Polyethylene-coated paper can be used as glossy paper, or when it is melt-extruded onto the surface of the base paper and coated, the matte surface or silky surface that can be obtained with ordinary photographic printing paper by so-called molding Can also be used.

A back coat layer can be provided on the support, and examples of components that can be added to the back coat layer include a white pigment, an aqueous binder, and other components.
Examples of white pigments contained in the backcoat layer include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, and aluminum silicate. , Diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide, white inorganic pigment, styrene And organic pigments such as polyethylene plastic pigments, acrylic plastic pigments, polyethylene, microcapsules, urea resins, and melamine resins.

Examples of the aqueous binder used in the backcoat layer include styrene / maleate copolymer, styrene / acrylate copolymer, polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationized starch, casein, gelatin, carboxy Examples thereof include water-soluble polymers such as methyl cellulose, hydroxyethyl cellulose, and polyvinyl pyrrolidone, and water-dispersible polymers such as styrene butadiene latex and acrylic emulsion.
Examples of other components contained in the backcoat layer include an antifoaming agent, an antifoaming agent, a dye, a fluorescent brightening agent, a preservative, and a water-proofing agent.

(Preparation of inkjet recording medium)
In the ink receiving layer of the ink jet recording medium of the present invention, for example, a coating liquid (coating liquid A) containing at least fine particles, a water-soluble resin, and the two or more organic cationic polymers is applied to the surface of the substrate. ) At the same time as the coating, (2) a basic solution having a pH of 7.1 or higher (in the middle of drying of the coating layer formed by the coating and before the coating layer exhibits reduced-rate drying) After applying the coating solution B), it is preferably formed by a method of crosslinking and curing the coating layer to which the basic solution is applied (wet-on-wet method; hereinafter sometimes referred to as “WOW method”). Here, the cationic polymer in the present invention may be contained in either the coating liquid A or the coating liquid B, but is preferably added to the coating liquid B from the viewpoint of preventing aggregation with the fine particles. The crosslinking agent is contained in at least one of the coating solution A and the coating solution B, and is particularly preferably contained in the coating solution A.
By providing the ink-receiving layer that has been crosslinked and cured in this manner, ink absorbability and prevention of cracking of the film can be improved.

  When the ink receiving layer is formed by the above-mentioned WOW method, a lot of mordant (including the cationic polymer in the present invention) is present near the surface of the ink receiving layer, so that the ink-jet coloring material (ink) is sufficiently mordanted and printed. This is preferable in terms of improving the water resistance of subsequent characters and images. A part of the mordant may be contained in the coating liquid A. In that case, the mordants of the coating liquid A and the coating liquid B may be the same or different. In addition, the porous ink receiving layer obtained as described above can absorb ink rapidly by capillary action, and can form dots with good roundness without ink bleeding.

In the present invention, an ink-receiving layer coating solution (coating solution A) containing at least fine particles (for example, vapor-phase process silica) and a water-soluble resin (for example, polyvinyl alcohol) is prepared, for example, as follows. be able to.
First, vapor phase silica fine particles and a dispersant are added to water (for example, silica fine particles in water are 10 to 20% by mass), and a high-speed rotating wet colloid mill (for example, “Claire” manufactured by M Technique Co., Ltd.) For example, at a high speed of 10,000 rpm (preferably 5000 to 20000 rpm), for example, for 20 minutes (preferably 10 to 30 minutes), followed by crosslinking agent (boron compound), polyvinyl alcohol ( PVA) can be prepared by adding an aqueous solution (for example, PVA having a mass of about 1/3 of the above-mentioned vapor-phase process silica) and dispersing under the same rotation conditions as described above. The obtained coating liquid is in a uniform sol state, and a porous ink-receiving layer having a three-dimensional network structure can be formed by coating this on a support by the following coating method and drying it.

  In addition, the preparation of the aqueous dispersion composed of the above-mentioned vapor phase method silica and a dispersant may be carried out by preparing a vapor phase method silica aqueous dispersion in advance and adding the aqueous dispersion to the aqueous dispersant solution. The aqueous solution may be added to the vapor phase silica aqueous dispersion, or may be mixed simultaneously. Further, instead of vapor phase silica aqueous dispersion, powder vapor phase silica may be used and added to the aqueous dispersant as described above.

  After mixing the gas phase method silica and the dispersant, the mixture is refined using a disperser, whereby an aqueous dispersion having an average particle size of 50 to 300 nm can be obtained. As a disperser used for obtaining the aqueous dispersion, various types of conventionally known dispersers such as a high-speed rotary disperser, a medium agitating disperser (ball mill, sand mill, etc.), an ultrasonic disperser, a colloid mill disperser, and a high pressure disperser. Although a disperser can be used, a stirrer-type disperser, a colloid mill disperser, or a high-pressure disperser is preferable from the viewpoint that the formed fine particles are efficiently dispersed.

In addition, a chaotic polymer can be used as the dispersant. Examples of the chaotic polymer include the aforementioned mordants. It is also preferable to use a silane coupling agent as the dispersant.
The amount of the dispersant added to the fine particles is preferably 0.1% to 30%, more preferably 1% to 10%.

  As a solvent in each step, water, an organic solvent, or a mixed solvent thereof can be used. Examples of the organic solvent that can be used for coating include alcohols such as methanol, ethanol, n-propanol, i-propanol, and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate, and toluene. .

  The ink receiving layer coating liquid is applied by a known coating method such as, for example, an extrusion die coater, an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, or a bar coater. it can.

  A basic solution (coating solution B) having a pH of 7.1 or higher can be applied to the coating layer simultaneously with or after the coating of the ink receiving layer coating solution (coating solution A). The liquid B) may be applied before the coating layer after coating becomes depleted. That is, after the application of the ink-receiving layer coating liquid (coating liquid A), the basic solution (coating liquid B) is preferably introduced while the coating layer exhibits a constant rate of drying.

  The basic solution (coating liquid B) having a pH of 7.1 or higher in the present invention contains a crosslinking agent and a mordant as necessary. The pH of the basic solution is preferably 7.3 or higher, more preferably 7.6 or higher. When the pH of the basic solution is less than 7.1, the crosslinking agent does not sufficiently perform the crosslinking reaction of the water-soluble polymer contained in the coating liquid A, and defects such as cracks occur in the ink receiving layer. There is a case.

  The basic solution (coating solution B) includes at least a basic substance (for example, ammonia, primary amines (ethylamine, polyallylamine, etc.), secondary amines (dimethylamine, triethylamine, etc.), tertiary amines ( N-ethyl-N-methylbutylamine, etc.), alkali metal or alkaline earth metal hydroxides) and / or salts of the basic substances.

  Here, “before the coating layer comes to show reduced drying” usually refers to a process for several minutes immediately after the coating of the coating liquid for the ink-receiving layer. This shows the phenomenon of “constant rate drying rate” in which the content of the solvent (dispersion medium) of the ink decreases in proportion to time. About the time which shows this "constant rate drying speed", it describes in chemical engineering handbook (pages 707-712, Maruzen Co., Ltd. issue, October 25, 1980), for example.

  As described above, after the coating solution is applied, the coating layer is dried until the coating layer exhibits reduced-rate drying. This drying is generally performed at 40 to 180 ° C. for 0.5 to 10 minutes (preferably 0.5 ~ 5 minutes). The drying time naturally varies depending on the coating amount, but the above range is usually appropriate.

  As a method of giving before the said coating layer comes to show reduction-rate drying, (1) The method of further apply | coating the coating liquid B on a coating layer, (2) The method of spraying by methods, such as a spray, (3 ) A method of immersing the support on which the coating layer is formed in the coating solution B, and the like.

  In the above method (1), examples of the coating method for coating the coating liquid B include a curtain flow coater, an extrusion die coater, an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, and a bar. A known coating method such as a coater can be used. However, it is preferable to use a method in which the coater does not directly contact the already formed first coating layer, such as an extrusion die coater, a curtain flow coater, a bar coater or the like.

  After the application of the basic solution (coating liquid B), it is generally heated at 40 to 180 ° C. for 0.5 to 30 minutes, and dried and cured. Especially, it is preferable to heat at 40-150 degreeC for 1 to 20 minutes.

  When the basic solution (coating liquid B) is applied simultaneously with the application of the ink receiving layer coating liquid (coating liquid A), the ink receiving layer coating liquid (coating liquid A) and the basic solution (coating liquid B) are used. The ink receiving layer can be formed by simultaneously coating (multilayer coating) on the support so that the ink receiving layer coating liquid (coating liquid A) is in contact with the support, and then drying and curing.

  The simultaneous coating (multilayer coating) can be performed by a coating method using, for example, an extrusion die coater or a curtain flow coater. After the simultaneous coating, the formed coating layer is dried. In this case, the drying is generally performed by heating the coating layer at 40 to 150 ° C. for 0.5 to 10 minutes, preferably 40 to 100. It is carried out by heating at a temperature of 0.5 to 5 minutes.

  When the above simultaneous coating (multilayer coating) is performed by, for example, an extrusion die coater, the two types of coating liquid discharged at the same time are close to the discharge port of the extrusion die coater, that is, before moving onto the support. A multilayer is formed, and in that state, the multilayer is applied on the support. Since the two-layer coating liquid layered before coating is likely to cause a cross-linking reaction at the interface between the two liquids when transferred to the support, the two liquids to be ejected are mixed in the vicinity of the discharge port of the extrusion die coater. As a result, thickening is likely to occur, which may hinder the application operation. Therefore, when applying simultaneously as described above, the barrier layer liquid (intermediate liquid) is interposed between the two liquids together with the application of the ink receiving layer coating liquid (coating liquid A) and the basic solution (coating liquid B). It is preferable to apply them simultaneously in a triple layer.

  The barrier layer solution can be selected without particular limitation. For example, an aqueous solution containing a trace amount of water-soluble resin, water, and the like can be given. The water-soluble resin is used in consideration of applicability for the purpose of a thickener and the like. For example, a cellulose resin (for example, hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose) And polymers such as polyvinylpyrrolidone and gelatin. The barrier layer solution may contain the above mordant.

  After the ink receiving layer is formed on the support, the ink receiving layer is subjected to, for example, super calender, gloss calender, etc., and is subjected to calender treatment through the roll nip under heat and pressure, so that surface smoothness, glossiness, It is possible to improve transparency and coating strength. However, the calendar process may cause a decrease in the porosity (that is, the ink absorptivity may be decreased), so it is necessary to set conditions under which the decrease in the porosity is small.

As roll temperature in the case of performing a calendar process, 30-150 degreeC is preferable and 40-100 degreeC is further more preferable.
Moreover, as a linear pressure between the rolls at the time of a calendar process, 50-400 kg / cm is preferable and 100-200 kg / cm is further more preferable.

In the case of ink jet recording, the thickness of the ink receiving layer needs to have an absorption capacity sufficient to absorb all of the droplets, and therefore needs to be determined in relation to the porosity in the layer. For example, if the ink amount is 8 nL / mm ² and the porosity is 60%, a film having a layer thickness of about 15 μm or more is required.
Considering this point, in the case of ink jet recording, the layer thickness of the ink receiving layer is preferably 10 to 50 μm.

The pore diameter of the ink receiving layer is preferably 0.005 to 0.030 μm, more preferably 0.01 to 0.025 μm in terms of median diameter.
The porosity and pore median diameter can be measured using a mercury porosimeter (trade name “Bore Sizer 9320-PC2” manufactured by Shimadzu Corporation).

In addition, the ink receiving layer is preferably excellent in transparency, as a guide, the haze value when the ink receiving layer is formed on a transparent film support is preferably 30% or less, More preferably, it is 20% or less.
The haze value can be measured using a haze meter (HGM-2DP: Suga Test Instruments Co., Ltd.).

  A polymer fine particle dispersion may be added to a constituent layer (for example, an ink receiving layer or a back layer) of the ink jet recording medium of the present invention. This polymer fine particle dispersion is used for the purpose of improving film properties such as dimensional stabilization, curling prevention, adhesion prevention, and film cracking prevention. The polymer fine particle dispersion is described in JP-A Nos. 62-245258, 62-1316648, and 62-110066. When a polymer fine particle dispersion having a low glass transition temperature (40 ° C. or lower) is added to the layer containing the mordant, cracking and curling of the layer can be prevented. Further, even when a polymer fine particle dispersion having a high glass transition temperature is added to the back layer, curling can be prevented.

  Further, the inkjet recording medium of the present invention is disclosed in JP-A Nos. 10-81064, 10-119423, 10-157277, 10-217601, 11-348409, and JP-A-2001-138621. 2000-43401, 2000-2111235, 2000-309157, 2001-96897, 2001-138627, JP-A-11-91242, 8-2087, 8-2090, 8 It can also be produced by the methods described in the publications Nos. -2091 and 8-2093.

  An undercoat layer may be provided on the support for the purpose of enhancing the adhesion between the ink receiving layer and the support and appropriately adjusting the electric resistance value.

  The ink receiving layer may be provided only on one side of the support, or may be provided on both sides of the support for the purpose of preventing deformation such as curling. When used in OHP or the like and the ink receiving layer is provided only on one side of the support, an antireflection film can be provided on the opposite surface or both sides for the purpose of enhancing light transmission. .

  In addition, by applying boric acid or a boron compound to the surface of the support on the side where the ink receiving layer is provided and forming the ink receiving layer thereon, the glossiness and surface smoothness of the ink receiving layer can be improved. In addition, it is possible to suppress aging blurring of an image after printing in a high temperature and high humidity environment.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples. In the examples, “parts” and “%” all mean “parts by mass” and “% by mass”.

(Production of support)
Wood pulp consisting of 100 parts of LBKP was beaten to 300 ml Canadian freeness with a double disc refiner, 0.5 parts of epoxidized behenamide, 1.0 part of anionic polyacrylamide, 0.1 part of polyamide polyamine epichlorohydrin, and 0. 5 parts were all added at an absolutely dry mass ratio to the pulp, and weighed with a long paper machine to make a base paper of 170 g / m ² .

In order to adjust the surface size of the base paper, 0.04% of a fluorescent whitening agent (“Whiteex BB” manufactured by Sumitomo Chemical Co., Ltd.) is added to a 4% aqueous solution of polyvinyl alcohol, and this is 0 in terms of absolute dry mass. The base paper was impregnated so as to have a density of 0.5 g / m ² , dried, and then subjected to a calendering process to obtain a base paper having a density adjusted to 1.05 g / cm ³ (g / cc).

After the corona discharge treatment was performed on the wire surface (back surface) side of the obtained base paper, high-density polyethylene was coated to a thickness of 19 μm using a melt extruder to form a resin layer composed of a mat surface. (Hereinafter, this resin layer surface is referred to as “back surface”). After the corona discharge treatment is further applied to the resin layer on the back side, as an antistatic agent, aluminum oxide (“Alumina sol 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (“Nissan Chemical Industries, Ltd.” “ Snowtex O ") and a 1: a dispersion dispersed in water at 2 weight ratio, dry mass was applied as a 0.2 g / m ^2.

  Furthermore, after the corona discharge treatment was performed on the felt surface (front surface) side on which the resin layer was not provided, 10% anatase-type titanium dioxide, a trace amount of ultramarine blue, and 0.01% fluorescent whitening agent (against polyethylene) Resin) and low density polyethylene with MFR (melt flow rate) of 3.8 is extruded to a thickness of 29 μm using a melt extruder, and a high gloss thermoplastic resin layer is formed on the surface side of the base paper. (Hereinafter, this highly glossy surface is referred to as a “front surface”) to obtain a desired support.

[Example 1]
(Preparation of coating liquid A for ink receiving layer)
In the following composition, (1) gas phase method silica fine particles, (2) ion-exchanged water, (3) “Charol DC-902P”, and (4) zirconyl acetate are mixed, and a bead mill made by Shinmaru Enterprises Co., Ltd. After being dispersed using “KD-P”, the following (5) polyaluminum chloride, (6) “SC-505”, (7) polyvinyl alcohol, (8) boric acid, (9) polyoxyethylene lauryl ether And (10) A solution containing ion-exchanged water was added and mixed to prepare an ink-receiving layer coating solution (A).

<Composition of ink receiving layer coating liquid A>
(1) Gas phase method silica fine particles (inorganic fine particles) 16.0 parts (“Leosil QS-30” manufactured by Tokuyama Corporation)
(2) 89.2 parts of ion exchange water
(3) 1.6 parts of polydimethyldiallylammonium salt (“Charol DC-902P” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 51% aqueous solution)
(4) Zirconyl acetate 1.3 parts ("Zircosol ZA-30" manufactured by Daiichi Rare Element Chemical Co., Ltd.)
(5) Polyaluminum chloride 2.3 parts ("Alphain 83" manufactured by Daimei Chemical Industry Co., Ltd.)
(6) Dimethylamine-epichlorohydrin-polyalkylenepolyamine polycondensate (“SC-505”, 50% aqueous solution manufactured by Hymo Co., Ltd.) 0.4 parts
(7) Polyvinyl alcohol (water-soluble resin) 50.6 parts ("PVA224" manufactured by Kuraray Co., Ltd., 7% aqueous solution)
(8) Boric acid (crosslinking agent) 0.65 parts
(9) 0.2 parts of polyoxyethylene lauryl ether (surfactant) (“Emulgen 109P”, 10% aqueous solution manufactured by Kao Corporation)
(10) 20.05 parts of ion exchange water

(Preparation of inkjet recording medium (1))
After the corona discharge treatment is applied to the front surface of the support, the coating liquid (A) for the ink receiving layer obtained above is applied to the front surface of the support using an extrusion die coater at 180 ml / m ² . The coating layer was dried at 80 ° C. (wind speed of 3 to 8 m / sec) with a hot air dryer until the solid content concentration of the coating layer became 20%. This coating layer exhibited a constant rate of drying during this period. Immediately after that, it was immersed in a basic coating solution (B) having the following composition for 30 seconds to deposit 15 g / m ² on the coating layer (step of applying a basic coating solution), and further at a temperature of 80 ° C. It was dried for 10 minutes (drying process). Thus, an inkjet recording medium (1) of the present invention provided with an ink receiving layer having a dry film thickness of 35 μm was produced.

<Composition of basic coating solution B>
(1) 93.05 parts of ion exchange water
(2) Boric acid (crosslinking agent) 0.65 parts
(3) 2.0 parts ammonium carbonate (Kanto Chemical Co., Ltd., reagent grade 1)
(4) 3.9 parts of zircoammonium carbonate ("Zircosol AC-7" manufactured by Daiichi Rare Element Chemical Industry Co., Ltd.)
(5) Polyoxyethylene lauric ether 0.2 part ("Emulgen 109P" manufactured by Kao Corporation)
(6) 0.2 part of MegaFuck "F1405" (Dainippon Ink Chemical Co., Ltd.)

[Example 2]
(Preparation of inkjet recording medium (2))
In Example 1, instead of 0.4 parts of “SC-505” manufactured by Hymo Co., Ltd. used in <Composition of Ink Receptive Layer Coating Liquid A>, a dicyandiamide-polyalkylene polyamine polycondensate (Daiichi Kogyo Seiyaku ( An ink jet recording medium (2) of the present invention was prepared in the same manner as in Example 1 except that 0.5 part of “Amigen NF” manufactured by Co., Ltd., 40% aqueous solution) was added.

[Example 3]
(Preparation of inkjet recording medium (3))
In Example 1, instead of 0.4 part of “SC-505” manufactured by Hymo Co., Ltd. used in <Composition of Ink Receptive Layer Coating Liquid A>, polyamidine (“SC-700” manufactured by Hymo Co., Ltd.) An ink jet recording medium (3) of the present invention was produced in the same manner as in Example 1 except that 0.7 part of a 30% aqueous solution) was added.

[Example 4]
(Preparation of inkjet recording medium (4))
In Example 1, except that 0.1 part of the following compound (1) was added as a chelating agent in <Composition of Ink Receptive Layer Coating Liquid A>, the same as in Example 1, for ink jet recording. A medium (4) was produced.

[Example 5]
(Preparation of inkjet recording medium (5))
In Example 2, except that 0.1 part of the following compound (1) was added as a chelating agent in <Composition of Ink-Receptive Layer Coating Liquid A>, the same as in Example 2, for inkjet recording of the present invention A medium (5) was produced.

[Example 6]
(Preparation of inkjet recording medium (6))
In Example 5, except that 4.0 parts of the following compound (2) (solid content: 25%) was further added as a sulfur-containing compound in <Composition of Ink-Receptive Layer Coating Liquid A>. Thus, an inkjet recording medium (6) of the present invention was produced.

[Comparative Example 1]
(Preparation of inkjet recording medium (7))
Ink jet recording of a comparative example in the same manner as in Example 1, except that 0.4 parts of “SC-505” manufactured by Hymo Co., Ltd. was not used in <Composition of Ink Receptive Layer Coating Liquid A>. A working medium (7) was produced.

[Comparative Example 2]
(Preparation of inkjet recording medium (8))
A comparison was made in the same manner as in Example 1 except that 1.6 parts of “Charol DC-902P” manufactured by Daiichi Kogyo Seiyaku Co., Ltd. were not used in <Composition of Ink Receptive Layer Coating Liquid A>. An example inkjet recording medium (8) was prepared.

(Evaluation test for ozone resistance)
Using the ink-jet printer “PM-G800” manufactured by Seiko Epson Corporation, solid images of magenta (M) and cyan (C) were printed on each of the ink-jet recording media obtained above. It was stored for 96 hours in an environment with a concentration of 10 ppm. The density of magenta (M) and cyan (C) before and after storage was measured using a reflection density meter “Xrite 938” manufactured by Xrite, and the residual ratio of the magenta density and cyan density was calculated. The results are shown in Table 1 below.

(Measurement of viscosity)
In the production of each ink jet recording medium, the liquid viscosity immediately after the preparation of the ink receiving layer coating liquid (A) and the liquid viscosity at 24 hours after the preparation were measured using a B-type viscometer “RB-80L” manufactured by Toki Sangyo Co., Ltd. Was measured under the conditions of a temperature of 30 ° C. and a rotational speed of 60 rpm, and the results are shown in Table 1 below.
The (I / O value) of the cationic polymer used in each example was also entered in Table 1 below. Here, since “Amigen NF” does not have a clear polymer structure, the average (I / O value) of the monomer components was defined as the (I / O value) of the polymer.

(Evaluation of coated surface)
For each ink jet recording medium, the surface state of the coated surface provided with the ink receiving layer was visually observed and evaluated according to the following criteria. The results are shown in Table 1 below.
[Standard]
◎ …… No coating defects such as paint streaks, bubbles, repellencies were found.
○ ………… There are some coating defects, but there are no practical problems.
×: There were many coating defects that could not be provided for practical use.

As apparent from Table 1 above, the ink jet recording medium (1-6) of the present invention containing an organic cationic polymer having an (I / O value) according to the present invention in the ink receiving layer is a comparative example. It was found to be superior in ozone resistance compared to those (7-8). Furthermore, the ozone resistance of the inkjet recording medium (4 to 6) containing a chelating agent is further excellent, and in particular, the ozone resistance of the inkjet recording medium (6) containing a chelating agent and a sulfur-containing compound is the most excellent. It was.
Furthermore, the ink receiving layer coating liquid of the ink jet recording medium (1-6) of the present invention has a low viscosity, a high stability, a good coated surface, and an ink jet recording medium excellent in productivity. It was found that a manufacturing method can be provided.

Claims (9)

  In an inkjet recording medium having an ink receiving layer on a substrate, the ink receiving layer is a water-soluble resin, and an organic cationic having an inorganic / organic ratio (I / O value) of less than 2.8 in an organic conceptual diagram. An ink jet recording medium comprising at least one polymer and at least one organic cationic polymer of 2.8 or more.   2. The ink jet recording medium according to claim 1, wherein the ink receiving layer further contains fine particles.   The mass content ratio of the organic cationic polymer having an inorganic / organic ratio (I / O value) of less than 2.8 and the organic cationic polymer of 2.8 or more is 1: 5 to 40: 1. The ink jet recording medium according to claim 1, wherein the ink jet recording medium is a recording medium.   The organic cationic polymer having an inorganic / organic ratio (I / O value) of less than 2.8 is dimethyldiallylammonium chloride and trialkylammonium salt acrylate or methacrylate, and trialkylammonium salt acrylate or methacrylate and styrene. The ink jet recording medium according to claim 1, wherein the recording medium is at least one selected from the group of copolymers.   The organic cationic polymer having an inorganic / organic ratio (I / O value) of 2.8 or more is polyallylamine, polyethyleneimine, polyvinylamine, polyamidine, dimethylamine-epichlorohydrin polycondensate, and dicyan-diamide. The ink jet recording medium according to claim 1, wherein the medium is at least one selected from the group of polycondensates.   6. The ink jet recording medium according to claim 1, wherein the ink receiving layer contains at least one chelating agent.   The ink jet recording medium according to claim 1, wherein the ink receiving layer contains at least one sulfur-containing compound.   The ink receiving layer is a layer obtained by crosslinking and curing a coating layer coated with a coating solution containing at least a water-soluble resin and the two or more kinds of organic cationic polymers, and the crosslinking and curing is the coating solution and / or A crosslinking agent is added to the following basic solution and (1) the coating solution is applied to form a coating layer, or (2) the coating layer formed by coating the coating solution is being dried. The coating layer is applied by applying a basic solution having a pH of 7.1 or more to the coating layer at any time before the coating layer exhibits reduced-rate drying. A method for producing an inkjet recording medium according to any one of the above.   An ink jet recording medium manufactured according to the manufacturing method according to claim 8.